Much of the power supplied to certain electrical devices is radiated from the device as heat. Prior-art methods for eliminating unwanted heat from electrical devices entailed placing the electrical device on a heat sink to draw the heat away from the device. The heat sink then radiates the unwanted heat into the nearby environment.
U.S. Pat. No. 5,777,427, ELECTRON EMISSION CATHODE HAVING A SEMICONDUCTOR FILM; A DEVICE INCLUDING THE CATHODE; AND A METHOD FOR MAKING THE CATHODE by Tanaka et al., describes a method for eliminating heat from a semiconductor device by application of a voltage between an anode and the semiconductor device. The applied voltage serves to cool the semiconductor device by drawing electrons from the semiconductor device.
Whether by radiating unwanted heat into the environment, or cooling the device by application of a voltage to the device, much of the power supplied to the electrical device is wasted. In fact, cooling the electronic device by application of a voltage actually requires more power since in addition to powering the electronic device, power needs to be supplied to the voltage (cooling) source.
With the miniaturization and integration of power electronic devices, heat dissipation densities can be greater than 1000 Watts per square centimeter (W/cm.sup.2). Thus for certain electrical devices, over 1000 Watts of power is wasted for every square centimeter area of heat dissipated from the device. Therefore a need exists for a method and apparatus for utilizing heat dissipated from an electrical device so that much of the power supplied to the device is not wasted during the process of heat dissipation.